| Name: Sabarinath M D |
| Affiliation: Indian Institute of Science Education and Research Kolkata |
| Conference ID: ASI2026_777 |
| Title: Geophysical Investigation of the Proposed Crater Site: Implications for Large Impact Structures in Planetary Context |
| Abstract Type: Poster |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Sabarinath M D(IISER Kolkata, Mohanpur - 741246, India), Anubhab Das(IISER Kolkata, Mohanpur - 741246, India) |
| Abstract: Large impact events play a fundamental role in shaping planetary crusts and are important for understanding long-term planetary evolution. However, the analysis of ancient or deeply modified impact structures remains challenging, particularly when these sites are obscured by sedimentation, volcanism, or tectonic overprinting. In this study, the proposed Shiva crater off the western continental margin of India is studied as a possible buried impact basin. Publicly available satellite gravity, magnetic anomaly, and bathymetric datasets are analysed and compared using a radial-profile and forward-modelling approach to assess whether the observed geophysical signatures are consistent with those expected from a large impact structure.
Annulus-averaged radial profiles centred on the proposed impact location reveal a very faint central gravity high, along with mild concentric variations at larger radii that are present across independent datasets. A distinct bathymetric rim is not observed; however, subtle slope variations are present, which may reflect post-impact modification, burial, or long-term thermal subsidence. Forward modelling using simplified density and magnetic contrasts shows that the first-order characteristics of the observed gravity profiles can be reproduced under reasonable assumptions, although uncertainties remain due to data resolution and other inherent factors.
Rather than providing a confirmation, this work focuses on demonstrating an easily adaptable geophysical workflow for testing hypotheses related to large, highly degraded impact structures. The approach is directly applicable to planetary bodies such as the Moon and Mars, where erosion-free yet volcanically or sedimentologically modified basins are common and ground truth is limited. The Shiva structure is therefore treated as a case study that highlights both the potential and the limitations of geophysical methods in investigating ancient planetary-scale impacts. |
